console.log([10, ...[], 20, ...[30, 40], 50]["length"]);
console.log([10, ...[], 20, ...[30, 40], 50][0]);
console.log([10, ...[], 20, ...[30, 40], 50][1]);
console.log([10, ...[], 20, ...[30, 40], 50][2]);
console.log([10, ...[], 20, ...[30, 40], 50][3]);
console.log([10, ...[], 20, ...[30, 40], 50][4]);
console.log([10, ...[], 20, ...[30, 40], 50][5]);
